Encapsulation (networking)

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Encapsulation of user data, in the Unix-style UDP stack. Each new layer includes the data from the previous layer, but each new layer is not able to identify which part of the data is the header or trailer from the previous layer. This effectively hides the information from lower layers.[1]

In computer networking, encapsulation is a method of designing modular communication protocols in which logically separate functions in the network are abstracted from their underlying structures by inclusion or information hiding within higher level objects.

The physical layer is responsible for physical transmission of the data. Link encapsulation allows local area networking and Internet Protocol (IP) provides global addressing of individual computers; Transmission Control Protocol (TCP) adds application or process selection, i.e., the port specifies the service such as a Web or TFTP server.[2]

In discussions of encapsulation, the more abstract layer is often called the upper layer protocol while the more specific layer is called the lower layer protocol. Sometimes, however, the terms upper layer protocols and lower layer protocols are used to describe the layers above and below IP, respectively.[2]

Encapsulation is a characteristic feature of most networking models, including both the OSI Model and TCP/IP suite of protocols.

See also[edit]


  1. ^ Forouzan, Behrouz A. (2010). TCP/IP protocol suite (4th ed. ed.). Boston: McGraw-Hill Higher Education. p. 23. ISBN 0073376043. 
  2. ^ a b "How Encapsulation Works Within the TCP/IP Model". learn-networking.com. 2008-01-27. Retrieved 2013-11-22.